That would mean she hasn’t seen the horrified expression on her face when she tries out a new modern world invention like the swivel chair, or her deadpan delivery of one-liners such as, “One can’t go to pieces at the death of every foreigner. We’d all be in a constant state of collapse whenever we opened a newspaper.”

Though these performances seem effortless, the Oscar-winning actress, who has won two Emmys for her role, admitted she’s quite a perfectionist. She told60 Minutes’ Steve Kroft that she’s afraid of “agonizing” over her role. Smith lamented, “It’s frustrating. I always see things that I would like to do differently and think, ‘Oh, why in the name of God did I do that?'”

Smith became a household name when she starred as the spunky private school teacher in The Prime of Miss Jean Brodie (1969), adapted from the Muriel Spark novel.

Smith’s interview, which aired Sunday, coincided with the third-season finale of the Emmy award-winning Downton Abbey, which follows the lives of an aristocratic family and their servants in early twentieth-century Britain.

Erica Ho was previously a reporter for TIME in Hong Kong where she wrote about technology, pop culture and Asian international affairs. Before that, she worked at Gizmodo, Lifehacker and AOL. She now currently runs Map Happy, a travel-oriented site.